1#!/usr/bin/python2
2#
3# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
4# Use of this source code is governed by a BSD-style license that can be
5# found in the LICENSE file.
6
7"""Command-line tool for checking and applying Chrome OS update payloads."""
8
9from __future__ import print_function
10
11import optparse
12import os
13import sys
14
15# pylint: disable=F0401
16lib_dir = os.path.join(os.path.dirname(__file__), 'lib')
17if os.path.exists(lib_dir) and os.path.isdir(lib_dir):
18  sys.path.insert(1, lib_dir)
19import update_payload
20
21
22_TYPE_FULL = 'full'
23_TYPE_DELTA = 'delta'
24
25
26def ParseArguments(argv):
27  """Parse and validate command-line arguments.
28
29  Args:
30    argv: command-line arguments to parse (excluding the program name)
31
32  Returns:
33    A tuple (opts, payload, extra_args), where `opts' are the options
34    returned by the parser, `payload' is the name of the payload file
35    (mandatory argument) and `extra_args' are any additional command-line
36    arguments.
37  """
38  parser = optparse.OptionParser(
39      usage=('Usage: %prog [OPTION...] PAYLOAD [DST_KERN DST_ROOT '
40             '[SRC_KERN SRC_ROOT]]'),
41      description=('Applies a Chrome OS update PAYLOAD to SRC_KERN and '
42                   'SRC_ROOT emitting DST_KERN and DST_ROOT, respectively. '
43                   'SRC_KERN and SRC_ROOT are only needed for delta payloads. '
44                   'When no partitions are provided, verifies the payload '
45                   'integrity.'),
46      epilog=('Note: a payload may verify correctly but fail to apply, and '
47              'vice versa; this is by design and can be thought of as static '
48              'vs dynamic correctness. A payload that both verifies and '
49              'applies correctly should be safe for use by the Chrome OS '
50              'Update Engine. Use --check to verify a payload prior to '
51              'applying it.'))
52
53  check_opts = optparse.OptionGroup(parser, 'Checking payload integrity')
54  check_opts.add_option('-c', '--check', action='store_true', default=False,
55                        help=('force payload integrity check (e.g. before '
56                              'applying)'))
57  check_opts.add_option('-D', '--describe', action='store_true', default=False,
58                        help='Print a friendly description of the payload.')
59  check_opts.add_option('-r', '--report', metavar='FILE',
60                        help="dump payload report (`-' for stdout)")
61  check_opts.add_option('-t', '--type', metavar='TYPE', dest='assert_type',
62                        help=("assert that payload is either `%s' or `%s'" %
63                              (_TYPE_FULL, _TYPE_DELTA)))
64  check_opts.add_option('-z', '--block-size', metavar='NUM', default=0,
65                        type='int',
66                        help='assert a non-default (4096) payload block size')
67  check_opts.add_option('-u', '--allow-unhashed', action='store_true',
68                        default=False, help='allow unhashed operations')
69  check_opts.add_option('-d', '--disabled_tests', metavar='TESTLIST',
70                        default=(),
71                        help=('comma-separated list of tests to disable; '
72                              'available values: ' +
73                              ', '.join(update_payload.CHECKS_TO_DISABLE)))
74  check_opts.add_option('-k', '--key', metavar='FILE',
75                        help=('Override standard key used for signature '
76                              'validation'))
77  check_opts.add_option('-m', '--meta-sig', metavar='FILE',
78                        help='verify metadata against its signature')
79  check_opts.add_option('-p', '--root-part-size', metavar='NUM',
80                        default=0, type='int',
81                        help=('override rootfs partition size auto-inference'))
82  check_opts.add_option('-P', '--kern-part-size', metavar='NUM',
83                        default=0, type='int',
84                        help=('override kernel partition size auto-inference'))
85  parser.add_option_group(check_opts)
86
87  trace_opts = optparse.OptionGroup(parser, 'Applying payload')
88  trace_opts.add_option('-x', '--extract-bsdiff', action='store_true',
89                        default=False,
90                        help=('use temp input/output files with BSDIFF '
91                              'operations (not in-place)'))
92  trace_opts.add_option('--bspatch-path', metavar='FILE',
93                        help=('use the specified bspatch binary'))
94  parser.add_option_group(trace_opts)
95
96  trace_opts = optparse.OptionGroup(parser, 'Block tracing')
97  trace_opts.add_option('-b', '--root-block', metavar='BLOCK', type='int',
98                        help='trace the origin for a rootfs block')
99  trace_opts.add_option('-B', '--kern-block', metavar='BLOCK', type='int',
100                        help='trace the origin for a kernel block')
101  trace_opts.add_option('-s', '--skip', metavar='NUM', default='0', type='int',
102                        help='skip first NUM occurrences of traced block')
103  parser.add_option_group(trace_opts)
104
105  # Parse command-line arguments.
106  opts, args = parser.parse_args(argv)
107
108  # Validate a value given to --type, if any.
109  if opts.assert_type not in (None, _TYPE_FULL, _TYPE_DELTA):
110    parser.error('invalid argument to --type: %s' % opts.assert_type)
111
112  # Convert and validate --disabled_tests value list, if provided.
113  if opts.disabled_tests:
114    opts.disabled_tests = opts.disabled_tests.split(',')
115    for test in opts.disabled_tests:
116      if test not in update_payload.CHECKS_TO_DISABLE:
117        parser.error('invalid argument to --disabled_tests: %s' % test)
118
119  # Ensure consistent use of block tracing options.
120  do_block_trace = not (opts.root_block is None and opts.kern_block is None)
121  if opts.skip and not do_block_trace:
122    parser.error('--skip must be used with either --root-block or --kern-block')
123
124  # There are several options that imply --check.
125  opts.check = (opts.check or opts.report or opts.assert_type or
126                opts.block_size or opts.allow_unhashed or
127                opts.disabled_tests or opts.meta_sig or opts.key or
128                opts.root_part_size or opts.kern_part_size)
129
130  # Check number of arguments, enforce payload type accordingly.
131  if len(args) == 3:
132    if opts.assert_type == _TYPE_DELTA:
133      parser.error('%s payload requires source partition arguments' %
134                   _TYPE_DELTA)
135    opts.assert_type = _TYPE_FULL
136  elif len(args) == 5:
137    if opts.assert_type == _TYPE_FULL:
138      parser.error('%s payload does not accept source partition arguments' %
139                   _TYPE_FULL)
140    opts.assert_type = _TYPE_DELTA
141  elif len(args) == 1:
142    # Not applying payload; if block tracing not requested either, do an
143    # integrity check.
144    if not do_block_trace:
145      opts.check = True
146    if opts.extract_bsdiff:
147      parser.error('--extract-bsdiff can only be used when applying payloads')
148    if opts.bspatch_path:
149      parser.error('--bspatch-path can only be used when applying payloads')
150  else:
151    parser.error('unexpected number of arguments')
152
153  # By default, look for a metadata-signature file with a name based on the name
154  # of the payload we are checking. We only do it if check was triggered.
155  if opts.check and not opts.meta_sig:
156    default_meta_sig = args[0] + '.metadata-signature'
157    if os.path.isfile(default_meta_sig):
158      opts.meta_sig = default_meta_sig
159      print('Using default metadata signature', opts.meta_sig, file=sys.stderr)
160
161  return opts, args[0], args[1:]
162
163
164def main(argv):
165  # Parse and validate arguments.
166  options, payload_file_name, extra_args = ParseArguments(argv[1:])
167
168  with open(payload_file_name) as payload_file:
169    payload = update_payload.Payload(payload_file)
170    try:
171      # Initialize payload.
172      payload.Init()
173
174      if options.describe:
175        payload.Describe()
176
177      # Perform payload integrity checks.
178      if options.check:
179        report_file = None
180        do_close_report_file = False
181        metadata_sig_file = None
182        try:
183          if options.report:
184            if options.report == '-':
185              report_file = sys.stdout
186            else:
187              report_file = open(options.report, 'w')
188              do_close_report_file = True
189
190          metadata_sig_file = options.meta_sig and open(options.meta_sig)
191          payload.Check(
192              pubkey_file_name=options.key,
193              metadata_sig_file=metadata_sig_file,
194              report_out_file=report_file,
195              assert_type=options.assert_type,
196              block_size=int(options.block_size),
197              rootfs_part_size=options.root_part_size,
198              kernel_part_size=options.kern_part_size,
199              allow_unhashed=options.allow_unhashed,
200              disabled_tests=options.disabled_tests)
201        finally:
202          if metadata_sig_file:
203            metadata_sig_file.close()
204          if do_close_report_file:
205            report_file.close()
206
207      # Trace blocks.
208      if options.root_block is not None:
209        payload.TraceBlock(options.root_block, options.skip, sys.stdout, False)
210      if options.kern_block is not None:
211        payload.TraceBlock(options.kern_block, options.skip, sys.stdout, True)
212
213      # Apply payload.
214      if extra_args:
215        dargs = {'bsdiff_in_place': not options.extract_bsdiff}
216        if options.bspatch_path:
217          dargs['bspatch_path'] = options.bspatch_path
218        if options.assert_type == _TYPE_DELTA:
219          dargs['old_kernel_part'] = extra_args[2]
220          dargs['old_rootfs_part'] = extra_args[3]
221
222        payload.Apply(extra_args[0], extra_args[1], **dargs)
223
224    except update_payload.PayloadError, e:
225      sys.stderr.write('Error: %s\n' % e)
226      return 1
227
228  return 0
229
230
231if __name__ == '__main__':
232  sys.exit(main(sys.argv))
233